I am interested in the importance of mutualistic interactions to maintaining native ecosystems. The implication of both local and national declines in the suite of native pollinators and seed dispersers in New Zealand have been only briefly considered, and the pollination and seed dispersal requirements of many native plants are still poorly understood. In addition the introduction and naturalisation of a range of bird and insect species, as well as flowering and fruiting plants, has altered the original pattern of these interactions. My research aims to identify mutualisms between the native flora and fauna, and to assess the impact of changes in these on ecosystem function. The research objective is to enable us to predict vulnerability in mutualistic interactions, so that management of native biodiversity can be optimised. I have been involved in research investigating the population dynamics of translocated NZ saddleback from a single source population to a range of sites, as well as projects investigating the behaviour and dispersal of alien mammals invading new islands. I have also been involved in research applying palynology in estuarine systems to correlate present vegetation patterns in space with successional sequences in time, and to measure the response of vegetation to past environmental factors such as human arrival in New Zealand.